Fragrance delivery systems are often described using terms such as “passive,” “active,” “continuous” or “burst.” As used herein, a passive system is one which delivers fragrance without the need for additional energy input to the system (e.g. ambient evaporation). In contrast, active systems require additional energy input, typically in the form of heating elements or fans (e.g. forced evaporation). Burst systems provide an instantaneous increase in fragrance intensity, for example, in the form of an aerosol or spray release. Any of the above systems may be further described as “continuous” or “on-demand.” For example, a passive or active delivery, by evaporation or other means, may be either continuous—requiring no initiation—or may be periodically initiated on-demand. Fragrance bursts are typically released on-demand. As used herein, the term “elevated intensity” is relative to the intensity provided by a single continuous delivery system and the terms “prolonged” or “prolonged intensity” are relative to the shorter-lived dissipation of purely atmospheric burst dispersions.
That being said, vapor-dispensing products typically include a volatizable material and a transport system configured to facilitate evaporation of the volatizable material into the surrounding air. Such volatizable materials include fragrances, air fresheners, deodorizers, odor eliminators, odor counteractants, insecticides, insect repellants, medicinal substances, disinfectants, sanitizers, mood enhancers, and aroma therapy compositions. Air fresheners are common exemplary vapor-dispensing devices and are often classified as passive, active or burst fresheners. Continuous passive release fresheners serve to provide a substantially constant fragrance intensity over extended periods and typically include a reservoir and a wick or other evaporative pathway and may include rudimentary intensity controls. Active fresheners, on the other hand, often employ heating elements and/or fans and may thus provide increased control and/or an increased range of fragrance intensity.
Burst fresheners are typically designed to provide instantaneous dispersions, for example, to combat transient or elevated odor levels, and lack the prolonged effect provided by continuous systems. Conventional burst systems employ aerosol propellants or mechanical type pumps and spray nozzles to create dispersions that typically dissipate quickly in the air. Alone, burst dispersions are short lived, characterized by a marked instantaneous increase in intensity followed by relatively rapid dissipation. As such, previous single-delivery systems are inadequate, leaving consumers to choose between passive, active, or burst products or to use multiple products resulting in mixing of different fragrances.
More recent systems have proposed combinations between basic continuous (passive or active) delivery mechanisms and burst delivery mechanisms. Such systems may thus provide either a continuous fragrance release with optional on-demand burst releases, or, on-demand burst releases with a supplemental passive release. So called combined continuous-burst dispensers provide but short-lived burst dispersions in addition to a continuous dispersion. In contrast, combined burst-semi-continuous dispensers provide short-lived atmospheric dispersions with subsequent temporary passive delivery but without any continuous delivery mechanism. Accordingly, such proposed systems lack means of providing a prolonged elevated fragrance intensity between and in addition to the two intensity extremes of their basic continuous and burst system progenitors.
Conventional products do not offer both supplemental burst releases and supplemental passive or active release in addition to a continuous fragrance release. Likewise, such conventional products do not provide prolonged, elevated fragrance release in addition to continuous fragrance release through a supplemental, on-demand passive or active delivery mechanism. Thus, there is a need for a vapor-dispensing device that overcomes these and other limitations of the prior art.